Only time will tell whether the Durban climate talks produced an historic breakthrough. It’s possible. What’s clear for now is that the Durban deal keeps the global climate effort intact and moving – however incrementally – in the right direction.

The deal is delicately poised between two eras – the fading age of Kyoto, and a new phase beyond Kyoto, with developed and developing countries presumably on a more equal footing.

Politically, there were four essential ingredients to the deal: Developing countries – and South Africa in particular – were adamant that Kyoto not die on African soil. Europe was adamant that it would only do another round of Kyoto if Durban launched new talks toward a comprehensive binding agreement. The United States (along with Japan, Australia, Canada and Russia) was adamant that any such agreement include major developing countries too. And, for the first time, China, India and other emerging economies appeared to agree.

The result: Europe (and a handful other developed countries) agreed to a “second commitment period” under Kyoto, with their new targets to be put in legal form next year. And parties launched the Durban Platform, aimed at producing a new deal by 2015 to take effect in 2020.

After days behind closed doors, and the conference more than 30 hours past its deadline, the final piece of the deal came in a quick, impromptu 3am scrum on the plenary floor in full view of observers and the press. It hinged on the same two fundamental issues that have shaped these talks from the start: how to define the legal nature of countries’ commitments, and how to balance responsibilities across developed and developing countries.

What the deal says about the binding-ness or the symmetry of a future agreement is less than crystal-clear. It launches a process “to develop a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties.” (Notably, there’s no reference to the Convention principle of “common but differentiated responsibilities,” which developing countries have traditionally used to fend off stronger commitments.)

The awkward phrasing is clearly a far cry from the Berlin Mandate, which launched the Kyoto negotiations with the dictate of emission targets for developed countries and no new commitments for developing countries. On the other hand, Kyoto is technically “applicable to all Parties.”

As for binding-ness, while it’s generally agreed that a protocol or other “legal instrument” would be legally binding, “agreed outcome with legal force” is an unfamiliar if not novel concoction. One can easily imagine countries coming back later with very different interpretations.

However squishy, the Durban Platform does for the first time present an opening for a balanced and binding agreement. The Copenhagen Accord and last year’s Cancún Agreements began a more balanced and gradualist approach to strengthening the international climate framework. Other decisions in Durban went further, particularly in the areas of finance and transparency.

But the arc begun in Copenhagen could go no further than a loose system of pledge-and-review. It’s important that the Durban Platform indeed be a platform for doing better. It sends a strong if not unambiguous signal that the intention is a binding agreement, and allows some time to get there. We will need it.

Elliot Diringer is the Executive Vice President of C2ES.